The Royal Birth Will Be Like Your Birth -- Only Posh

As the duchess gets closer to her due date, she probably has a birth plan, which includes where she'll deliver and whether she'll do so with or without painkillers. She could give birth vaginally or opt for a cesarean section – as gamblers have guessed, assuming that Middleton is "too posh to push."

Victoria "Posh Spice" Beckham, who was pregnant during the royal wedding with her fourth child, had all four children by elective cesarean section. Instead of giving birth vaginally, she opted to have her babies surgically removed from her abdomen.

Elective c-sections have become increasingly common in the United States, too, but it's not for everyone, Ashton said. It's "major abdominal surgery" that comes with certain risks, and it can at least two weeks to recover, she said.

"This is controversial even within the field [of OBGYNs]," Ashton said. "There are a lot of women who have significant fear of vaginal delivery, and it's a real thing. It doesn't make it right or wrong."

Murphy said she thinks that Middleton will give birth vaginally, but if she has a c-section, she won't be the first royal to do so. Queen Elizabeth II was born via c-section, she said.